Cyberbullies could exploit new Facebook tool

Attackers could post on other people's pages

A security vendor warned that a new Facebook feature could be exploited by cyberbullies.

According to F-Secure, the social network's new 'reply to this email to comment on this status' gives attackers a way to post messages on other people's Facebook pages.

These messages could include personal attacks that seem to come from a user but are actually written by someone who has compromised that person's email account, for instance.

The intent of the feature is to allow Facebook users to respond directly from their email when they receive notifications that include messages that have been posted to their Facebook accounts.

They can respond without having to go to the Facebook site first, eliminating a step and thereby saving time.

But eliminating that step can also leave a crack in Facebook's armor, according to F-Secure security adviser for North America Sean Sullivan.

Authenticating to the Facebook site before writing a reply drops out of the equation, so someone other than account holders can post.

"They can put words in my mouth," he says.

If a user's email account is compromised via phishing or direct hacking, spammers can respond to any Facebook notifications they come across, Sullivan says. It has posted a demonstration of how this can work here.

Facebook users can opt out of receiving the email notifications altogether by adjusting their settings.